A/C - Diagnosis & Repair of Refrigerant Leaks

88mazda04

Category 16
Applicable Model/s All Model with A/C
Subject DIAGNOSIS & REPAIR OF A/C REFRIGERANT LEAKS
Bulletin No. 033/88
Issued 6/30/88
Revised






DESCRIPTION

When diagnosing customer complaints regarding insufficient cooling and a refrigerant leak is suspected, please follow these procedures for locating and repairing the leak in order to prevent unnecessary component replacement.
Check the outlet air volume and temperature. (However, the outlet temperature will vary according to ambient conditions, 35 -45~F is normal.)

Verify the compressor clutch operation. (The compressor will not operate if the system is empty of refrigerant.)



Following indication shows low charge condition.
1. Visually check all components for obvious leaks and signs. Also, check the fittings by hand for tightness.

NOTE:
Some leaks may have an oil stain around leak area.

2. Use the electric leak detector to locate the leak.

When using leak detector:
a) the system should be at least partially charged.
b) the detector probe should be moved slowly at a rate of about 1 inch a second.



3. Whenever possible, the detector probe should be held underneath the components since the refrigerant is heavier than air.
HINT:
Hold the electric leak detector probe near the drain hose. Refrigerant from evaporator core may be detected through the water drain hose.



Most of the leaks from the pipe connection can be fixed with O-ring replacement and proper torquing, but, please pay attention to the failure on pipe and components.
After replacing O-rings or components, evacuate the system at least 10 minutes and hold the vacuum further 10 minutes.

If the vacuum does not drop, no leak is evident. Charge the system with proper amount of refrigerant.


Remove the cooling unit and look for the oil stains.

HINT:
Before removing the cooling unit, charge the system with a leak-detectorrefrigerant which contains a dye. After operating the system for a period of time, any leaks will be identified by a dye stain around the leaking area.

Replace the O-ring at the expansion valve connection, or evaporator core.